Future studies will include 1) investigation of factors regulating synaptic transmission mediated by neurotransmitters, such as gamma- aminobutyric acid (GABA) and dopamine, which have been implicated in neurologic disease; 2) research on the possible sites and mechanisms of action of drugs which impair or augment neural function in these systems; 3) clinical evaluation of drugs which appear potentially useful for the treatment of movement disorders; and 4) clinical characterization of the symptoms and etiology of these disorders.